Primary relay for induction regulators



E. LEHR PRIMARY RELAY FOR INDUCTION REGULATORS Filed Sept. 8, 1924INVENTOR Edwin [c /fir BY W ATTORNEY WITNESSES:

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Patented Oct 2 2, 192 8.

, UNITED STATES EDWIN LEHR, OF EDGEWUOI) PARK, PENNSYLVANIA, ASSIGNOR TWESTINGHOUSE PATENT OFFICE.

ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

PRIMARY' RELAY FOR INDUCTION REGULATORS.

Application filed September 8, 1924. Serial No. 736,426.

My inventionrelates to regulator systems and has special relation toelectric relays uti lized for regulating thevoltage, or any otherelectrical quantity, "of alternating-current circuits. 1

I In a motor driven feeder regulator of the tion regulator by means of acontact-making voltmeter controlling a floatingcontactfdevice thatco-operates with twofixed contact members. The gap between the contactmembers determinesthe permissible voltage variation beforethe-regulatorwill be operated in either direction. With the. controlmagnet of the contact-making voltmeter undampechthe regulator-operatesfreely to corroot the slight voltage changes of short duration. Such aregulator also has a tendency to hunt or to carry the correction beyondthe desired normal value in either direction. 'i i One object of myinvention'is to provide a contact-making relay, that is sensitive tovoltage changes in the circuit to be regulated to govern the operationof the regulator.

Another object of my invention is to provide a relay of theabove-indicated character that shall be sensitive to slight variationsin voltage changes, should the variations in voltage be maintained for apredetermined time, but shall not be sensitive to temporary slightchanges in voltage values.

Another object of my invention is to pro vide a relay of theabove-indicated character that will control the regulator to preventhunting action. 2

My invention will be better understood by reference to theaccompanying'drawing in which the single figure is a iagrammatic view ofthe apparatus and arrangement thereof used in an embodiment of myinvention.

Referring to the drawing, an induction regulator 1 is connected to acircuit 23,

the primary coil 4 being connected in parallel with the circuit and thesecondary coil 5 being connected in series with the circuit. An electricmotor 6 is provided to actuate the coil 5 relatively to the coil 1, inaccordance with the correction required to maintain a constantvoltage inthe circuit 23.

A relay 7, or contact-making voltmeter, is provided to controlthe'operation of the motor 6. The relay is operated by means of anelectro-magnet provided with a coil 8 that is energized from thetransformer-9,

connectedacross the circuit 2-3. The core llof the electromagnetoperates a lever 12 pivoted .at 13 and carrying a pair of contactmembers 14L and 15. Co-operating withthe contact members 14 and 15 areauxiliary members 16 and 17 mounted on the bellcrank lever 18, pivotedat the point 19. A

pair of flexible connecting members, such as helical springs 21 and 22are provided, one of these members 21 connecting the levers 12 and 18,and the other connecting the lever 18- to a fixed support 23. To thelever 18 is attached a device for retarding the motion thereof, such asa dashpot 24.

The contact members of the'primary relay 7 are connected to selectivelyenergize operating coils 251 or 26 ofthe secondary relay The operatingcoil 25, when energized, operates a relay to close the contact members28 and the contact members 29, causing the motor 6 touop'eratc in onedirection. The

operating coil 26, when energized, operates a relay to close contactmembers 31 and 32 to operate the motor 6 in the opposite direction. Aswill be noted by an inspection of the drawing, the motor 6 isillustrated as a three-phase motor energized from a separate three-phasesource of supply, the motor leads 33, 34: and 35 being connected to thealternating-current source 36, 37 and 38 in a particular phase relation,in accordance with the en ergization of the relay coils 25 or 26 of thesecondary relay 27.

The operation of the device is as follows: Changes in the voltage of thecircuit 23 cause a change in the setting of the relay 7 and, therefore,a change in the position of the lever 12. 1 Changing the position of thelever 12 in the one direction or the other increases or decreases thetension on the spring 21, so that it becomes greater than or less thanthe tension on the spring 22, thus actuating the lever 18 in the onedirection or the other, Should slight changes 'in thesetting of thelever 12-be maintained for only a short period, the contact members1401' 15 would fail to make contact with the contact member 16 or17,,due to the space between the contact members. Should this changedsetting of the relay be maintained, however, the lever 18 wouldgradually move to a position of rest such that the tension on thesprings 21 and 22 would be equal, and thus effect engagement betweencontact members 14s and 16 or 15 and 17. The dashpot 24L acts to retardthe motion of the lever 18 and the contact members 16 and 17 whereby,for slight changes in the line voltage that are maintained for only ashort time, no correction by the induction regulator will be effected.

Should a large change in the voltage of the line occur, the degree ofchange .in the position of the lever 12 and the contacts 1 1 and 15would be sufiicient to cause engagement of one of these contact membersimmediately. That is, the motion of the contact members l'or '15 wouldbe su'llicient to bridge the space causing engagement with contactmembers 16 or 17 without the latter being moved to a new position.

lVhile I have described my contact-making voltmeter as applied :to thecontrol of an induction regulator, it is obvious that it may be used tocontrol any form of regulator, and it may be connected to be sensitiveto current changes, or vto any other electrical quantity, as well as tobe sensitive to voltage changes.

Many modifications within the spirit and scope of my invention willoccur to those skilled in the art and I do not wish to be limited otherthan by the scope of the appended claims.

I claim as my invention:

1. Ina regulator, .an electromagnet energized in accordance with thequantity to be regulated, a pair rofcontact members actuated by saidelectromagnet, a second pair of contact members co-operating with thefirst-named contact members, and resilient means for actuating, saidsecond pairofcontact members, means for varying the bias of saidresilient means in accordance with achangein the position of said firstpair of contact members.

2. In a regulator, @an electromagnet energized in accordance with thequantity to be regulated, a pair of contact members actuated by saidmagnet, a second pair of contact members cooperating with thefirst-named contact members, and resilient means connected between saidpairs of contact members for actuating said second pair of contactmembers in accordance with variations in the position of saidfirst-named contact members.

3. In a contact making relay, an electromagnet, a pair of contactmembers operated by said electromagnet, a pair of auxiliary contactmembers co-operating with said first-named contact members, a resilientconnection between'said electromagnetand said auxiliary contact membersfor actuating said auxiliary contact membersyand means for retarding theaction of said auxiliary contact members.

4. In a contact making relay,a-pair of contact members, a lever forsupporting said contact members, an electromagnet operativelyconnectedto said lever, a pair of auxiliary contact members and a leverfor-supporting said auxiliary contact members, a

resilient connection between said levers for subscribed my name this 3rdday of Septem ber, 1924.

EDWIN LEHR.

, adamant,

